In a communication network, interference can be caused by neighbouring communication, like wired communication sharing the same medium or wireless communications sharing the same resource like a frequency band. As an example, Zigbee devices are low cost/low power wireless devices that may operate at a frequency band of 2.4 GHz with a transmission power of 1 mW (0 dBm). This frequency band is used by other technologies like Bluetooth, WiFi or IEEE 802.11 wireless Local Area Network (WLAN). Some other interference may occur from other devices in this band like microwave ovens. It is understood that WLAN devices pose the most serious issue for the operation of Zigbee devices for the transmission power of WLAN devices is substantially higher than the transmission power of Zigbee devices, typically 100 mW or 20 dBm. Moreover, WLAN devices, used everywhere, operates on a bandwidth broader than the one of Zigbee devices.
As a consequence, it has been observed that a Zigbee network operates poorly with a WLAN network coexistence. The coexistence performance depends on the distance between WLAN interference and Zigbee devices. Since several applications of Zigbee (lighting of building, medical or patient monitoring) need a reliable communication within an environment which will likely contains at least one WLAN network, it is a need to propose a solution to reduce the amount of interference to enable the Zigbee network to operate.